Truing tool for grinding wheels



Malh 21, 1939 w. STADELBAUER 2,151,572

TRUING TOOL FOR GRINDING WHEELS Filed June 1l, 1958 f mi? Illlllll 4 'E d A4 ll/l Patented Mar. 21, 1939 TRUING TOUL FOR GRINDING WHEELS Walter Stadelbauer, Dusseldorf, Germany Application June 11, 1938, Serial No. 213,158 In Germany March 4, 1936 1 Claim.

The truing of grinding wheels is effected with tools whose truing Wheels roll on the grinding wheel. Such tools may be divided into two categories: l. Tho-se with milling cutters composed of several cutting discs arranged loosely side by side and which operate without lubrication. As the peripheral speed of the grinding wheel (normally metres per second) at the small diameter of the truing Wheel, which is generally between 20 and 40 inillimetres, is fully transmitted, speeds of rotation of 12,000 to 20,000 revolutions per minute are obtained. It is evident that strong friction and braking occur on the journals of the truing tool. This results in heavy wear of the bearings of the truing tools and a large consumption of truing Wheels.

The second type of the known truing` tools operates with rigid truing milling cutters which are pressed together on .a sleeve, either a ball bearing or some kind of grease lubrication being provided, In the case of these truing wheels the friction on the journals is reduced. However, when truing the side faces of grinding wheels, which require truing just the same as the periphery, the working conditions for the rigid truing milling cutters are still more unfavourable than for loose disc-Wheels as, for example when truing the side of a grinding wheel 200 millimetres in diameter with a rigid truing cutter millimetres in diameter and 25 millimetres wide, the outermost disc on the left of the cutter must rotate at the full peripheral speed of the grinding wheel (25 metres/second, that is 16,000 R. P. M.) whereas the outermost disc on the right of the cutter, which works on a diameter of 150 millimetres, only has a peripheral speed of about 19` metres per second, that is, must perform 12,000 R. P. M. The difference in the number of revolutions of the left and right cutting discs amounts therefore to 4000 R. P. which, owing to the rigid construction of the truing cutter, cannot be compensated and results in a large consumption of truing tools.

The invention relates to a truing tool which overcomes this objection because a ball bearing is employed Whose advantages are combined with those of a loose arrangement of the individual cutter discs.

The shape of the individual cutter nut 8.

The individual cutter discs 9 and the spacing rings I0 are loosely mounted on the race cylinder 4.

When truing the side faces of a grinding wheel, its rotation is transmitted to the ball bearings. The compensation of the different circumferential speeds takes place in that the individual cutter discs sit loosely on their race cylinder 4 and are rotatable the one relatively to the others. Therefore, each cutter disc rotates at a different speed on the grinding wheel.

The consumption of truing wheels is thus reduced to a fraction of the normal consumption, as each individual truing disc assumes exactly the peripheral speed of the grinding wheel at the portion it is actually working, and as in this manner al1 frictional effect of the grinding wheel is eliminated.

I claim:

A truing tool for grinding Wheels, comprising in combination an axle, a sleeve loosely mounted on said axle, ball bearings supporting said sleeve on said axle to ensure frictionless rotation of said sleeve on said axle, a carrier on said sleeve and rotatable therewith, and a plurality of separate truing elements loosely mounted on said rotatable carrier, said truing elements being rotatable relatively to said carrier and at the same time ro-tatable at different angular speeds relatively to one another.

WALTER STADELBAUER. 

